Here’s an interesting item from on a possible softening of China’s one-child policy. Faster population in China will not necessarily be the salvation of that economy, and faster economic growth from China will not necessarily be the salvation of the world economy – but it would at least be a start.

The one child policy was introduced in 1978, ostensibly as a way to keep a lid on population growth and alleviate strains on resources and the environment. Although there are a few loopholes, the policy basically limits married couples to having one child and one child only.

Although the social costs from the policy have been evident for a long time, the economic ones have not. At the same time that the population policy was put in place, China also opened up trade and essentially became the world’s factory. Economic growth in skyrocketed, so much so that China became the second largest economy in the world (behind only the United States) in 2011.

The growth was fueled by a huge population of young workers who moved from rural areas to the cities and worked in the factories. There was plenty of labor, and it powered plenty of production. According to data from the United Nations database, the population aged from 15 to 24 grew by 14 percent – about 29 million – over the period from 2000 to 2010.

But let’s do the math: that population was largely either born before the one-child policy, or were the children of those for n before the one-child policy. Today, a twenty-year old seeking factory work would have had to have been born in 1992 – meaning that they would almost certainly have had to have been an only child. A fifteen year old would have had to have been born in 1997, and may have been the only child of only children.

No surprise then that the outlook for young labor from China is dismal. Again using the data from the United Nations database, the population aged 15 to 24 is set to drop by 21 percent – that translates into 47 million 2010 and 2020. It does not bode well for labor supply, or for creating a new consumer class that will demand goods from the reset of the world. And let’s not even talk about what it means in terms of paying for an aging population.

So a relaxing of the one-child policy would be a good idea. A good idea, but not one that can happen quickly enough to make a difference particularly quickly.

Right now, China’s economy is feeling the impact of a European economy in recession. The last batch of economic indicators – on everything from property prices to manufacturing activity – has been awful, so much so that most forecasters do not expect much more than 7 to 8 percent growth for China this year. That might sound okay, but for China it really is something close to an effective recession.

And it may not be in recession, but the U.S. is not looking particularly solid at the moment. Between the aftermath of the recession and the looming fiscal cliff ahead, the speed limit on that economy is set to slow. That means the world needs growth, substantial growth, to come from somewhere else.

Reversing the one-child policy may not make a huge difference in a hurry, but not reversing it is only going to add to the problems of a world in transition .